一、管内非稳定流的计量法和问题点。一般在起动或停止流体机械及调节流量时,管内流速变动很大。在工业上采用这样非稳定流的场合很多。特别是近年来,非稳定流的问题更加引人注目,因为原来还不成问题的紊流式变动流,随着流速的不断增大,亦相应以很大力量在不断变化。而如果机械仍然是轻型构造是不行的,由于机械尺寸变大,马力也要格外增大,这样,非稳定的强度就不易掌握了。此外,非稳定流的问题不仅在工业方面,例如在人体内血管里血的流动亦是一样,因此,也因关系 First, the tube instability flow measurement method and problem points. Generally start or stop the fluid machinery and adjust the flow, the tube flow velocity varies widely. In the industrial use of such instability flow a lot of occasions. In recent years, in particular, the problem of unsteady flow has drawn even more attention because the turbulently-changing flow, which was not yet a problem, has been constantly evolving with great strength as its flow rate continues to increase. However, if the machine is still lightweight, it will not work. Due to the large mechanical size, the horsepower will also be greatly increased. As a result, the unstable strength will not be easy to grasp. In addition, the problem of unsteady flow is not only in the industrial field, but also in blood flow in a human body, and therefore,